Pyrazol-4-yl phosphates and insecticidal and acaricidal use

ABSTRACT

Pyrazol-4-yl phosphates of the formula ##STR1## wherein R 1  represents a lower alkyl group, R 2  is a lower alkoxy group or a lower alkylthio group, R 3  represents hydrogen or a lower alkoxycarbonyl group, X is oxygen or sulfur atom, Y represents a lower alkyl, a lower alkoxy or a lower alkylthio group, a halogen atom, nitro or trifluoromethyl, and n is zero or an integer of 1, 2 or 3, or Yn represents an alkylidenedioxy containing 1 to 3 carbon atoms, have marked insecticidal-acaricidal activity against household pests, plant pests, mites, etc. without substantial toxicity to warm-blooded animals and fishes.

This application is a continuation of Ser. No. 304,258 filed Sept. 14, 1981, now abandoned, which is a continuation of Ser. No. 136,460 filed Mar. 31, 1980, now abandoned.

The present invention relates to pyrazolyl phosphoric acid esters which are novel compounds, a method for the preparation thereof, and an insecticidal-acaricidal composition.

In more particular, the present invention relates to pyrazolyl phosphoric acid esters represented by the general formula (I): ##STR2## wherein R¹ represents a lower alkyl group; R² represents a lower alkoxy or a lower alkylthio group; R³ is hydrogen or a lower alkoxycarbonyl group; X is oxygen or sulfur; Y is a lower alkyl, a lower alkoxy or a lower alkylthio group, a halogen atom, nitro or trifluoromethyl; and n is zero or an integer of 1, 2 or 3 a method for the preparation of these esters, and an insecticidal-acaricidal composition containing them as an effective ingredient.

The present inventors, with a specific view to the development of insecticides or acaricides which could be produced profitably on an industrial scale and could be safely applied without substantial toxicity to warm-blooded animals and fishes, without presenting any substantial drug damage to plants, synthesized a large number of organic compounds and conducted repeated investigation through biological and other tests. As a result, it has been found that the compounds according to the present invention as represented by the general formula (I) hereinbefore described exhibit an excellent insecticidal-acaricidal activity against plant damaging insects, mites parasitic on plants and unsanitary pests including ticks parasitic on warm-blooded animals, etc. and that they can be profitably produced on an industrial scale.

In the general formula (I), the lower alkyl group designated by R¹ means straight-chain or branched alkyls of 1 to 4 in carbon atom number, and examples thereof that may be utilized include methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, etc.; the lower alkoxy group represented by R² means alkoxy groups of 1 to 4 in carbon atom number, being exemplified by methoxy, ethoxy, n-propoxy, isopropoxy, n-butoxy, isobutoxy, sec-butoxy, etc.; the lower alkylthio group represented by R² alkylthio groups of 1 to 4 in carbon atom number, being exemplified by methylthio, ethylthio, n-propylthio, isopropylthio, n-butylthio, isobutylthio, sec-butylthio, etc.; the lower alkoxycarbonyl group designated by R³ may for example be alkoxycarbonyl groups in which the alkoxy has 1 to 4 carbon atoms, such as methoxycarbonyl and ethoxycarbonyl; among the groups shown by Y, the lower alkyl, lower alkoxy and lower alkylthio groups have the same meanings as defined for R¹ and R², respectively, and examples of the lower alkyl group may include t-butyl in addition to those described hereinbefore; as examples of the halogen atoms there may be mentioned fluorine, chlorine, bromine and iodine atoms; n represents a number of substituents of Y, and when n is not less than 2, these substituents may be the same or different. Furthermore, in the event that the groups represented by Y are lower alkoxy groups with n equal to 2, within the scope of the present invention falls the case where two of the alkoxy groups combine to form an alkylidene-dioxy group containing 1 to 3 carbon atoms such as methylenedioxy and isopropylidenedioxy groups.

A desirable class of compounds (I) comprises the compounds wherein R¹ represents a lower alkyl group, R² is a lower alkylthio group, R³ is hydrogen, X is oxygen or sulfur atom, Y represents a halogen atom or trifluoromethyl, and n is an integer of 1, 2 or 3. A family of the particularly important compounds comprises the compounds of the general formula (I) wherein R¹ means ethyl group, with R² representing n-propylthio group. In addition, important is a group of the compounds wherein R³ means hydrogen.

The compounds according to the present invention have a strong insecticidal-miticidal activity against many insects and mites and, while they retain such excellent action, possess the characteristic feature of being relatively low in oral, acute toxicity. Those compounds having the combination of R¹ being ethyl and R² n-propylthio, which are the especially important compounds among the ones according to the present invention, exhibit excellent preventive and exterminating effect, particularly, against noxious insects such as Lepidoptera and mites or ticks, while being low in acute toxicity toward warm-blooded animals when orally ingested. This activity manifests itself not only when the compound of this invention is directly applied to pests, for example by spraying it on host plants, but also when the compound (I) absorbed by plants from the roots, leaves, stems or the like comes into contact with pests as, for example, the latter suck or gnaw the plant.

The compounds (I) according to the present invention may be produced by a method conventional per se, and, for example, by esterifying a compound of the general formula (II) as shown below or its salt: ##STR3## wherein R³, Y and n are as defined hereinbefore, with a compound of the general formula (III): ##STR4## wherein Hal is a halogen atom; R¹, R² and X are as defined hereinbefore. The esterification reaction is desirably conducted in the presence of an acid-binding agent.

Employed as the appropriate acid-binding agent are, especially, tertiary amines such as trialkylamine, pyridine and γ-collidine, or hydroxides, carbonates and bicarbonates of alkali and alkaline earth metals and alcoholates of alkali metals such as sodium carbonate, potassium carbonate, sodium hydrogencarbonate, sodium hydroxide, potassium hydroxide, sodium methylate and sodium ethylate. Among salts of 4-hydroxypyrazole compounds of the general formula (II), the corresponding alkali metal salts are suitable, and the sodium, potassium salts, etc. are desirable. Normally, the reaction is desirably conducted in an appropriate solvent, and useful solvents are, for example, water, alcohols such as methanol, ethanol, n-propanol, isopropanol, n-butanol and t-butanol, aromatic hydrocarbons such as benzene, toluene and xylene, halogenated hydrocarbons such as methylene chloride, chloroform and carbon tetrachloride, ethers such as ethyl ether, dioxane and tetrahydrofurane, ketones such as acetone and methyl ethyl ketone, nitriles such as acetonitrile, etc., acid amides such as dimethyl-formamide, etc., esters such as ethyl acetate, etc., and sulfoxides such as dimethylsulfoxide, etc.

As to the reaction temperature, the temperature at which the reaction may proceed can be suitably selected from the range of -20° C. to 150° C., and the temperature of 0° C. to 100° C. is suitable. The reaction goes to completion within 0.5 to 10 hours, whereby the conclusion of the reaction may be confirmed by thin-layer chromatography, etc.

After the conclusion of the reaction, the resultant reaction mixture is subjected to a procedure conventional per se to obtain the desired compound. For example, the reaction solution is directly washed with water or freed of the solvent, and then extracted with an organic solvent such as toluene, etc., followed by washing with water, drying over, e.g., anhydrous sodium sulfate, and distilling off the solvent to obtain the compound of the present invention. If desired, the compound may be further purified by such procedures as distillation, recrystallization and column chromatography.

Moreover, the compound (I) according to the present invention may be produced by esterifying a compound of the general formula (II) or its salt with a compound designated by the general formula (IV): ##STR5## wherein R², X and Hal are as defined hereinbefore, in the same manner as the reaction of a compound (II) with one of (III) as described hereinbefore, to obtain a compound represented by the general formula (V): ##STR6## wherein R², R³, X, Y, Hal, and n are as defined hereinbefore, followed by reacting the esterified compound with a compound designated by the formula R¹ OH whose R¹ is as defined hereinbefore, under the same conditions as those of the reaction of compound (II) with compound (III) provided that water and alcohols are not suitable as the solvent.

In addition, among the compounds of the general formula (I), a compound designated by the general formula (VI) ##STR7## wherein R¹, R³, Y and n have the same meaning as above, and R⁵ means a lower alkyl group, may be produced by reacting a metal or ammonium salt of O-lower-alkyl-O-(1-phenylpyrazol-4-yl)phosphorothioic acid designated by the general formula (VII): ##STR8## wherein R¹, R³, Y and n are as defined hereinbefore and M is a metal atom or ammonium radical, with an alkylating agent, as conventionally utilized, represented by the general formula (VIII):

    Hal--R.sup.5, (R.sup.5 O).sub.2 SO.sub.2 or R.sup.5 OSO.sub.2φ(VIII)

wherein Hal represents a halogen atom; R⁵ is as defined hereinbefore and φ means phenyl group.

The lower alkyl group designated by R⁵ is exemplified by methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl groups, etc.

The reaction may be conducted under the conditions similar to those in the reaction of a compound of the general formula (II) with one of (III) as described hereinbefore, and, in the case of a branched, lower alkyl halide being utilized, the reaction may be favorably carried out by prolonging the reaction time slightly. A starting compound of the general formula (VII) is produced by the normally utilized, known methods; namely, by the procedure of reacting O-lower alkyl-O-(1-phenylpyrazol-4-yl)phosphorochloridothionate the compounds represented by the general formula (V) wherein X is sulfur atom, R² is a lower alkoxy group and Hal is chlorine atom, with alkali metal, or of reacting O,O-di-lower alkyl-O-(1-phenylpyrazol-4-yl)phosphorothionate, the compounds represented by the general formula (I) wherein X is sulfur atom and R² is a lower alkoxy group, in anhydrous alcohol, with sodium hydrogen sulfide, sodium alkyl mercaptide, sodium xanthate or potassium xanthate, etc.

The starting compound of the general formula (II) which is used in these reactions may be produced by the procedure as shown in the following equation and described in Annalen der Chemie, 313 12 (1900) or procedures similar thereto: ##STR9##

In addition, the present inventors carried out research work on a novel process for producing the starting compound of the general formula (II) (wherein R³ ═H) which is industrially advantageous, and found out the route described below that can provide a compound of the general formula (II) (wherein R³ ═H) under mild conditions and in increased yield. In other words, the method according to the present invention is highly valuable as an industrial production process, and many of the starting compounds of the general formula (II) (wherein R³ ═H) according to the present invention may be produced in accordance with the method. ##STR10##

The method comprises allowing diazonium salts designated by the general formula (X) to act on 4-haloacetoacetic acid represented by the general formula (IX) in the presence of a base to produce 3-halopyruvaldehyde phenylhydrazones designated by the general formula (XI) and subjecting the obtained compound to ring closure reaction in the presence of a base to produce the compounds of the general formula (II) (wherein R³ ═H).

The reaction that provides 3-halopyruvaldehyde phenylhydrazones represented by the general formula (XI) is normally conducted at a temperature of -10° C. to 30° C. Water is suitable as the solvent but, so as to prevent the resultant crystals from being burst by carbon dioxide gas evolved, alcohols such as methanol, ethanol and propanol may be added. Utilizable as the base are organic carboxylic acid salts, carbonates, hydrogencarbonates, hydroxides, etc. of alkali and alkaline earth metals such as sodium acetate, potassium acetate, sodium propionate, potassium propionate, sodium carbonate, potassium carbonate, sodium hydrogen carbonate, potassium hydrogen carbonate, sodium hydroxide and potassium hydroxide.

Then, the reaction that affords a compound of the general formula (II) (wherein R³ ═H) from a compound of the general formula (XI) is conducted in the presence of a base. Useful as the base are hydroxides, carbonates and hydrogen carbonates of alkali and alkaline earth metals as well as alcoholates of alkali metals such as sodium carbonate, potassium carbonate, sodium hydrogen carbonate, potassium hydrogen carbonate, sodium methylate and sodium ethylate, and desirable, among others, are strongly basic ones such as sodium hydroxide, potassium hydroxide and alcoholates of alkali metals. The amount of a base that is useful in the reaction, from an economical point of view, is suitably employed in the proportion of 1 to 3 moles to 1 mole of the compound of (XI), although the use of a large excess may be justifiable. The reaction is preferably carried out in a solvent, and utilizable as the solvent are, for example, water; alcohols such as methanol, ethanol, n-propanol, iso-propanol, n-butanol, and t-butanol; ethers such as ethyl ether, dioxane and tetrahydrofuran; ketones such as acetone and methyl ethyl ketone; nitriles such as acetonitrile, etc.; acid amides such as dimethylformamide, etc.; and sulfoxides such as dimethyl sulfoxide, etc. The reaction usually proceeds at a temperature within the range of from -20° C., to 100° C., and proceeds easily even at a temperature of not higher than 0° C. in alcohols, when sodium hydroxide, potassium hydroxide, alcoholate of alkali metals, or the like is employed as a base.

The present method, even when the reaction is conducted continuously without isolating the compound (XI) in the course of the reaction process, can afford the desired compound (II) (wherein R³ ═H) in a high yield.

Illustrated in the following are the examples of synthesis of the starting compound in accordance with the production process as described hereinbefore.

REFERENCE EXAMPLE A Synthesis of 1-(4-chlorophenyl)-4-hydroxypyrazole (Compound No.e)

In 50 ml of methanol is dissolved 4.0 g of sodium hydroxide and, when 9.3 g of 3-chloropyruvaledehyde 4-chlorophenylhydrazone is added to the solution at room temperature, it dissolves immediately and the temperature of the solution rises to about 40° C. After being stirred for 1 hour, methanol is distilled off, and 50 ml of water is added to the resultant residue to remove insolubles by filtration. Following neutralization with concentrated hydrochloric acid, the precipitate is recovered by filtration, washed with water and dried. Recrystallization from toluene yields 6.4 g of the subject compound as needle-like crystals. m.p. 127° C. to 128° C.

REFERENCE EXAMPLE B Synthesis of 1-(4-chlorophenyl)-4-hydroxypyrazole (Compound No.e)

4.0 g of sodium hydroxide is dissolved in 50 ml of water, in which is suspended 9.3 g of 3-chloropyruvaldehyde 4-chlorophenylhydrazone. The suspension is stirred at 50° C. for 3 hours. The crystals dissolve gradually, and the suspension becomes a homogeneous dark-red solution. The solution is cooled and the insolubles are removed by filtration, then the remaining solution is neutralized with concentrated hydrochloric acid. The resulting precipitates are collected by filtration, washed with water and dried. Recrystallization from toluene yields 5.7 g of the subject compound. m.p. 127° to 128° C.

REFERENCE EXAMPLE C Synthesis of 1-(2,4-dichlorophenyl)-4-hydroxypyrazole (Compound No. n)

27.0 g of 3-chloropyruvaldehyde 2,4-dichlorophenylhydrazone is suspended in 100 ml of ethanol. To the suspension is added at room temperature 12 g of sodium hydroxide dissolved in 10 ml of water. After stirring the mixture for 2 hours ethanol is distilled off, and water is added to the resultant residue to dissolve it. Insolubles are removed by filtration, and the filtrate is neutralized with glacial acetic acid. The precipitate is recovered by filtration, washed with water and dried. Recrystallization from toluene results in 17.3 g of the subject compound in the yield of 87%. m.p. 148° to 149° C.

Illustrated in the following Table are the compounds of the general formula (II) (R³ ═H) as synthesized according to the procedures of Reference Examples A through C.

                  TABLE                                                            ______________________________________                                          ##STR11##                    (II)                                             No      Y.sub.n       n     melting point, °C.                          ______________________________________                                         a        --           0     118-120                                            b       4-Br          1     157-159                                            c       2-Cl          1     105-106                                            d       3-Cl          1     98-99                                              e       4-Cl          1     127-128                                            f       4-F           1     155-157                                            g       4-I           1     203-205                                            h       2-CH.sub.3    1     128-130                                            i       4-CH.sub.3    1     125-127                                            j       4-n-C.sub.3 H.sub.7                                                                          1     101-102                                            k       4-CH.sub.3 O  1     111-112                                            l       4-CH.sub.3 S  1     127                                                m       3-CF.sub.3    1     96-97                                              n       2,4-Cl.sub.2  2     148-149                                            o       3,4-Cl.sub.2  2     152-154                                            p       3,5-Cl.sub.2  2     125-127                                            q       2,4-(CH.sub.3).sub.2                                                                         2     122-124                                            r       2,6-(CH.sub.3).sub.2                                                                         2     169-170                                            s       2-F, 4-Cl     2     137-139                                            t       2-CH.sub.3, 4-Cl                                                                             2     102-104                                            u       2-CH.sub.3, 5-NO.sub.2                                                                       2     128-130                                                     ##STR12##    2     125-126                                            w       2,4,5-Cl.sub.3                                                                               3     181-183                                            ______________________________________                                    

REFERENCE EXAMPLE D Synthesis of 3-chloropyruvaldehyde 4-chlorophenylhydrazone (Compound No. f')

In a mixture of 500 ml of water and 250 ml of concentrated hydrochloric acid is dissolved 128 g of p-chloroaniline. To this solution is added dropwise a solution of 69 g of sodium nitrite in 100 ml of water, while the reaction temperature is maintained at 0° C. Then, to the reaction mixture is added a solution of 136.5 g of 4-chloroacetoacetic acid in 200 ml of water, while the reaction temperature is maintained within the range from 0° C. to 5° C., followed by further addition of a solution of 164 g of sodium acetate in 300 ml of water, whereupon yellow precipitate is produced while bubbling vigorously. The reaction mixture is stirred at a room temperature until the bubbling ceases, followed by collecting the crystals by filtration, washing with water and drying, whereby 224 g of the subject compound is obtained. Yield 97%. m.p. 190° C.-192° C. (decomp.)

Illustrated in the following Table are the starting compounds of the general formula (XI) synthesized by the same procedure as described in Reference Example D.

                  TABLE                                                            ______________________________________                                          ##STR13##                                                                     No.    Hal    Y.sub.n      n   melting point, °C.*                      ______________________________________                                         a'     Br      --          0   178-180                                         b'     "      4-Br         1   182-184                                         c'     "      2-Cl         1   97-99                                           d'     "      3-Cl         1   152-154                                         e'     "      4-Cl         1   175-177                                         f'     Cl     4-Cl         1   190-192                                         g'     Br     4-F          1   178-180                                         h'     "      4-I          1   170-172                                         i'     "      2-CH.sub.3   1   105-108                                         j'     "      4-CH.sub.3   1   158-160                                         k'     "      4-n-C.sub.3 H.sub.7                                                                         1   120-121                                         l'     "      4-CH.sub.3 O 1   138-140                                         m'     "      3-CF.sub.3   1   121-123                                         n'     "      2,4-Cl.sub.2 2   132-134                                         o'     "      3,4-Cl.sub.2 2   168-170                                         p'     "      3,5-Cl.sub.2 2   181-183                                         q'     "      2,4-(CH.sub.3).sub.2                                                                        2   125-127                                         r'     "      2,6-(CH.sub.3).sub.2                                                                        2   98- 99                                          s'     "      2-F, 4-Cl    2   133-135                                         t'     "      2-CH.sub.3, 4-Cl                                                                            2   158-160                                         u'     "      2-CH.sub.3, 5-NO.sub.2                                                                      2   170-173                                         v'     "                                                                                      ##STR14##   2   136-137                                         w'     "      2,4,5-Cl.sub.3                                                                              3   153-155                                         ______________________________________                                          Remarks:-                                                                      *Melting points indicated are all the decomposition temperature.         

The phosphorochloridates represented by the general formula (III) or (IV) may be easily produced by the procedures already known or similar thereto.

The compounds of (I) according to the present invention are effective for controlling unsanitary pests, insects parasitic on plants, and mites.

In more particular, the compounds according to the present invention and preparations containing the same are effective especially for prevention and extermination of injurious insects of the order Hemiptera such as Eurydema rugosa, Scotinophara lurida, Riptortus clavatus, Stephanitis nashi, Laodelphax stiatellus, Nephotettix cincticeps, Unaspis yanonensis, Aphis glycines, Lipaphis pseudobrassicae, Brevicoryne brassicae, and Aphis gossypii; injurious insects of the order Lepidoptera such as Spodoptera litura, Plutella xylostella, Pieris rape crucivora, Chilo suppressalis, Plusia nigrisigna, Halicoverpa assulta, Leucania separate, Mamestra brassicae, Adoxophyes orana, Syllepte derogate, Cnaphalocrocis medinalis, Phthorimaea operculella, etc.; injurious insects of the order Coleoptera such as Epilachna vigintioctopunctata, Aulacophora femoralis, Phyllotreta striolata, Oulema orgzae and Echinocnemus squameus; injurious insects of the order Diptera such as Musca domestica, Culex pipiens pallens, Tabanus trigonus, Hylemya antiqua and Hylemyl platura; injurious insects of the order Orthoptera such as Locusta migratoria, Gryllotalpa africana, etc.; injurious insects of the order Blattaria such as Blattella germanica, Periplaneta fuliginosa, etc.; spider mites (the order Tetranychidae) such as Tetranychus urticae, Panonychus citri, Tetranychus kanzawai, Tetranychus cinnabarinus, Panonychus ulmi and eriophyid mites (Eriophyidae) such as Aculus pelekassi; ticks such as Ixodidae; such nematodes as Aphelenchoides besseyi, and the like.

For use as an insecticidal-acaricidal agent, the compound (I) according to this invention may take any of the known application formulations of agricultural chemicals. Thus, for example, one or more species of compound (I) are dissolved or dispersed in a suitable liquid carrier or admixed with, or adsorbed on, a suitable solid carrier to prepare an emulsifiable concentrate, oil solution, wettable powder, dust, granule, tablet, spray, paint, ointment or the like. If necessary, emulsifiers, suspension aids, spreading agents, penetrating agents, wetting agents, thickeners, stabilizers, etc. may also be incorporated in such compositions. These preparations can be produced by known manufacturing methods.

The content of the active component in insecticidal-miticidal preparations, although it varies depending upon their application purposes, is suitably about 10 to 90 percent by weight for the emulsifiable concentrates, wettable powder, etc., 0.1 to 10 percent by weight in the oil preparations, powder or dusts, etc., and 1 to 20 percent by weight for the granules. Furthermore, these concentrations may be properly changed with the application purposes, while the emulsifiable concentrates, wettable powder and the like, prior to their application, may be advantageously diluted and extended (up to 100 to 100,000 times, for example) appropriately with water, etc. to be dispersed therein.

Suitable as the liquid carriers to be employed are, for example, water, alcohols (e.g., methyl alcohol, ethyl alcohol, ethylene glycol, etc.), ketones (e.g., acetone, methyl ethyl ketone, etc.), ethers (e.g., dioxane, tetrahydrofurane, cellosolve, etc.), aliphatic hydrocarbons (e.g., gasoline, kerosene, light oil, fuel oil, machine oil, etc.), aromatic hydrocarbons (e.g., benzene, toluene, xylene, solvent naphtha, methylnaphthalene, etc.), halogenated hydrocarbons (e.g., chloroform, carbon tetrachloride, etc.), acid amides (e.g., dimethylformamide), esters (e.g., ethyl acetate, butyl acetate, glycerol esters of fatty acids, etc.), nitriles (e.g., acetonitrile), and other solvents, and one kind or a mixture of not less than two kinds of these is used.

Examples of useful solid carriers include powder of plant origin (e.g., soybean meal, tobacco powder, wheat flour, wood flour, etc.), powder of mineral origin (e.g., clay such as kaolin, bentonite and acid clay, talc such as talcum powder and pegotite powder, silica such as diatomaceous earth and mica powder, and the like), alumina, sulfur powder, activated carbon, etc., and one kind or a mixture of not less than two kinds of these is employed.

The ointment excipients are exemplified by polyethylene glycol, pectin, polyhydric alcohol esters of higher fatty acids such as glycerol monostearate, cellulose derivatives such as methylcellulose, sodium arginate, bentonite, higher alcohols, polyhydric alcohols such as glycerol, petrolatum, white petrolatum, liquid paraffin, lard, a variety of oils of plant origin, lanolin, lanolin anhydricum, hardened oil, resins, and the like, out of which one or not less than two kinds, directly or added with various surfactants, can be properly selected.

Among the surfactants which are useful as emulsifiers, spreaders, penetrants, dispersing agents, etc., employable as occasion demands are soaps, polyoxyaryl esters (e.g., Nonal® produced by Takemoto Oils & Fats Co., Ltd.), alkyl sulfates (e.g., Emal 10®, Emal 40®, etc. produced by Kao Atlas Co., Ltd.), alkyl sulfonates (e.g., Neogen® Neogen TR®, etc. produced by Daiichi Kogyo Seiyaku Co., Ltd.; Neoperex® produced by Kao Atlas Co., Ltd.), polyethylene glycol ethers (e.g., Nonipol 85®, Nonipol 100®, and Nonipol 160® produced by Sanyo Chemical Industries Co., Ltd.), polyhydric alcohol esters (e.g., Tween 20® and Tween 80® produced by Kao Atlas Co., Ltd.), and the like. In addition, the compounds of the present invention may be used in mixture by formulating them with for example, other kinds of insecticides (pyrethrin-based insecticides, organic phosphorus insecticides, carbamate insecticides, naturally occurring insecticides, etc.), acaricides, nematocides, herbicides, plant hormone preparations, plant growth control substances, fungicides and bactericides (e.g. copper based fungicides, organic chlorinated fungicides, organo-sulfur fungicides, phenol based fungicides, etc.), synergists, attractants, repellents, coloring matters, fertilizers, etc.

The composition containing the compound (I) can be employed to control the above-mentioned insects, mites or ticks attacking for example, dry field harvest, such as cabbages, soy beans, maize, cotton, and tobacco; fruit trees of apples, oranges, etc. The composition can also be applied to cattle directly or the inside and outside of cattle barns or poultry houses. The amount of the effective component to be used is usually within the range of from ca. 50 g to ca. 5 kg per ha., preferably from ca. 100 g to ca. 3 kg per ha.

The following examples serve to illustrate the present invention but should not be construed as imposing any limitations on the present invention.

EXAMPLE 1 Production of O-ethyl-O-(1-phenylpyrazol-4-yl)-S-n-propylphosphorothiolate (Compound No. 4)

In 50 ml of methanol is dissolved 0.5 g of metallic sodium, and 3.2 g of 1-phenyl-4-hydroxypyrazole is added thereto. Complete removal of methanol under reduced pressure gives sodium salt of 1-phenyl-4-hydroxypyrazole. The sodium salt is suspended in 60 ml of methyl ethyl ketone, and 4.0 g of O-ethyl-S-n-propylphosphorochloridothiolate is added to the suspension, followed by stirring at room temperature for 3 hours. After the conclusion of the reaction, methyl ethyl ketone is ditilled off, and toluene is added to the residue. The toluene layer is washed with water, and dried over anhydrous sodium sulfate. After distilling off toluene, the residue is purified by silica-gel column chromatography (developing solvent; chloroform). In this way, there is obtained 4.9 g of the subject compound in slightly yellow, oily form. n_(D) ²⁸ 1.5407.

EXAMPLE 2 Production of O-ethyl-O-(1-phenylpyrazol-4-yl)-S-n-propyl phosphorothiolothionate (Compound No. 5)

In 60 ml of acetone is suspended 3.6 g (0.02 mol) of sodium salt of 1-phenyl-4-hydroxypyrazole, and 4.4 g of O-ethyl-S-n-propyl phosphorochloridothiolothionate is added to the suspension. The mixture is heated under reflux for 3 hours, followed by removal of acetone by evaporation. To the residue is added toluene. The toluene layer is washed with water and dried over anhydrous sodium sulfate. Toluene is distilled off, and the residue is purified by silica-gel column chromatography (developing solvent: chloroform). By the above procedure, there is obtained 4.7 g of slightly yellow and oily compound as captioned above. n_(D) ³⁰ 1.5783.

EXAMPLE 3 Production of O-ethyl-O-[1-(4-chlorophenyl)pyrazol-4-yl]-S-n-propyl phosphorothiolate (Compound No. 16)

In 60 ml of acetonitrile is dissolved 3.9 g of 1-(4-chlorophenyl)-4-hydroxypyrazole, and 2.0 g of triethylamine is added thereto. Then, 4.0 g of O-ethyl-S-n-propyl phosphorochloridothiolate, followed by stirring at 50° C. for 3 hours. Acetonitrile is then distilled off and purification is conducted in accordance with the procedure of Example 1, yields 5.2 g of slightly yellow and oily compound as captioned above. n_(D) ²⁴ 1.5604.

EXAMPLE 4 Production of O-ethyl-O-[3,4-dichlorophenyl)pyrazol-4-yl]-S-n-propyl phosphorothiolate (Compound No. 31)

In 60 ml of methyl ethyl ketone is dissolved 4.6 g of 1-(3,4-dichlorophenyl)-4-hydroxypyrazole, and 2.8 g of potassium carbonate and 4.0 g of O-ethyl-S-N-propyl phosphorochloridothiolate, followed by stirring at 50° C. for 2 hours. Purification carried out in accordance with the procedure of Example 1 yields 5.9 g of the slightly yellow and oily compound as captioned above. n_(D) ²⁷ 1,5737.

EXAMPLE 5 Production of O-ethyl-O-[1-(4-chlorophenyl)pyrazol-4-yl]-S-n-propyl phosphorothiolate (Compound No. 16)

To 60 ml of ethanol are added 6.8 g of sodium O-ethyl-O-[1-(4-chlorophenyl)pyrazol-4-yl]phosphorothiolate and 2.7 g of n-propyl bromide, followed by stirring at 70° C. for 8 hours. The resultant inorganic salt is filtered off, ethanol being removed, and to the residue is added toluene. The toluene layer is washed with water and dried. Purification carried out in accordance with the procedure of Example 1 yields 5.0 g of slightly yellow and oily compound as captioned above. n_(D) ²⁴ 1.5604.

Shown in the following Table 1 are compounds produced in the same manner as in Examples 1 to 5, inclusive of those obtained in Examples 1 to 5.

                                      TABLE 1                                      __________________________________________________________________________      ##STR15##                                                                     Comp. No.                                                                            R.sup.1                                                                           R.sup.2                                                                             R.sup.3                                                                               X Y.sub.n n Physical constant                             __________________________________________________________________________     1     CH.sub.3                                                                          OCH.sub.3                                                                           H      S --      0 n.sub.D.sup.28 1.5696                         2     C.sub.2 H.sub.5                                                                   OC.sub.2 H.sub.5                                                                    H      S --      0 n.sub.D.sup.26 1.5520                         3     C.sub.2 H.sub.5                                                                   OC.sub.3 H.sub.7 (n)                                                                H      S --      0 n.sub.D.sup.28 1.5425                         4     C.sub.2 H.sub.5                                                                   SC.sub.3 H.sub.7 (n)                                                                H      O --      0 n.sub.D.sup.28 1.5407                         5     C.sub.2 H.sub.5                                                                   SC.sub.3 H.sub.7 (n)                                                                H      S --      0 n.sub.D.sup.30 1.5783                         6     C.sub.2 H.sub.5                                                                   OC.sub.3 H.sub.7 (n)                                                                COOC.sub.2 H.sub.5                                                                    S --      0 n.sub.D.sup.26 1.5432                         7     C.sub.2 H.sub.5                                                                   SC.sub.3 H.sub.7 (n)                                                                COOC.sub.2 H.sub.5                                                                    O --      0 n.sub.D.sup.20 1.5434                         8     C.sub.2 H.sub.5                                                                   SC.sub.3 H.sub.7 (n)                                                                COOC.sub.2 H.sub.5                                                                    S --      0 n.sub.D.sup.20 1.5683                         9     C.sub.2 H.sub.5                                                                   SC.sub.3 H.sub.7 (n)                                                                H      O 4-Br    1 n.sub.D.sup.20 1.5755                         10    C.sub.2 H.sub.5                                                                   SC.sub.3 H.sub.7 (n)                                                                H      S 4-Br    1 n.sub.D.sup.27 1.6025                         11    C.sub.2 H.sub.5                                                                   OC.sub.2 H.sub.5                                                                    H      S 2-Cl    1 n.sub.D.sup.24 1.5516                         12    C.sub.2 H.sub.5                                                                   SC.sub.3 H.sub.7 (n)                                                                H      O 2-Cl    1 n.sub.D.sup.24 1.5493                         13    C.sub.2 H.sub.5                                                                   SC.sub.3 H.sub.7 (n)                                                                H      O 3-Cl    1 n.sub.D.sup.20 1.5655                         14    C.sub.2 H.sub.5                                                                   SC.sub.3 H.sub.7 (n)                                                                H      S 3-Cl    1 n.sub.D.sup.24 1.5922                         15    C.sub.2 H.sub.5                                                                   OC.sub.2 H.sub.5                                                                    H      S 4-Cl    1 n.sub.D.sup.24 1.5635                         16    C.sub.2 H.sub.5                                                                   SC.sub.3 H.sub.7 (n)                                                                H      O 4-Cl    1 n.sub.D.sup.24 1.5604                         17    C.sub.2 H.sub.5                                                                   SC.sub.3 H.sub.7 (n)                                                                H      S 4-Cl    1 n.sub.D.sup.20 1.5933                         18    C.sub.2 H.sub.5                                                                   SC.sub.3 H.sub.7 (n)                                                                H      O 4-F     1 n.sub.D.sup.20 1.5368                         19    C.sub.2 H.sub.5                                                                   SC.sub.3 H.sub.7 (n)                                                                H      S 4-F     1 n.sub.D.sup.28 1.5695                         20    C.sub.2 H.sub.5                                                                   SC.sub.3 H.sub.7 (n)                                                                H      O 4-I     1 n.sub.D.sup.20 1.6000                         21    C.sub.2 H.sub.5                                                                   OC.sub.2 H.sub.5                                                                    H      S 2-CH.sub.3                                                                             1 n.sub.D.sup.24 1.5517                         22    C.sub.2 H.sub.5                                                                   SC.sub.3 H.sub.7 (n)                                                                H      O 2-CH.sub.3                                                                             1 n.sub.D.sup.25 1.5525                         23    C.sub.2 H.sub.5                                                                   SC.sub.3 H.sub.7 (n)                                                                H      O 4-CH.sub.3                                                                             1 n.sub.D.sup.25 1.5409                         24    C.sub.2 H.sub.5                                                                   SC.sub.3 H.sub.7 (n)                                                                H      O 4-C.sub.3 H.sub.7 (n)                                                                  1 n.sub.D.sup.20 1.5446                         25    C.sub.2 H.sub.5                                                                   SC.sub.3 H.sub.7 (n)                                                                H      S 4-CH.sub.3 O                                                                           1 n.sub.D.sup.28 1.5757                         26    C.sub.2 H.sub.5                                                                   SC.sub.3 H.sub.7 (n)                                                                H      O 4-CH.sub.3 S                                                                           1 n.sub.D.sup.20 1.5883                         27    C.sub.2 H.sub.5                                                                   SC.sub.3 H.sub.7 (n)                                                                H      O 3-CF.sub.3                                                                             1 n.sub.D.sup.20 1.5169                         28    C.sub.2 H.sub.5                                                                   SC.sub.3 H.sub.7 (n)                                                                H      S 3-CF.sub.3                                                                             1 n.sub.D.sup.20 1.5445                         29    C.sub.2 H.sub.5                                                                   SC.sub.3 H.sub.7 (n)                                                                H      O 2,4-Cl.sub.2                                                                           2 n.sub.D.sup.27 1.5586                         30    C.sub.2 H.sub.5                                                                   SC.sub.3 H.sub.7 (n)                                                                H      S 2,4-Cl.sub.2                                                                           2 n.sub.D.sup.20 1.5893                         31    C.sub.2 H.sub.5                                                                   SC.sub.3 H.sub.7 (n)                                                                H      O 3,4-Cl.sub.2                                                                           2 n.sub.D.sup.27 1.5737                         32    C.sub.2 H.sub.5                                                                   SC.sub.3 H.sub.7 (n)                                                                H      S 3,4-Cl.sub.2                                                                           2 n.sub.D.sup.20 1.5982                         33    C.sub.2 H.sub.5                                                                   SC.sub.3 H.sub.7 (n)                                                                H      O 3,5-Cl.sub.2                                                                           2 n.sub.D.sup.26 1.5698                         34    C.sub.2 H.sub.5                                                                   OC.sub.2 H.sub.5                                                                    H      S 2,4-(CH.sub.3).sub.2                                                                   2 n.sub.D.sup.27 1.5361                         35    C.sub.2 H.sub.5                                                                   SC.sub.3 H.sub.7 (n)                                                                H      O 2,4-(CH.sub.3).sub.2                                                                   2 n.sub.D.sup.27 1.5355                         36    C.sub.2 H.sub.5                                                                   SC.sub.3 H.sub.7 (n)                                                                H      O 2,6-(CH.sub.3).sub.2                                                                   2 n.sub.D.sup.28 1.5264                         37    C.sub. 2 H.sub.5                                                                  SC.sub.3 H.sub.7 (n)                                                                H      O 2-F,4-Cl                                                                               2 n.sub.D.sup.28 1.5481                         38    C.sub.2 H.sub.5                                                                   SC.sub.3 H.sub.7 (n)                                                                H      O 2-CH.sub.3,4-Cl                                                                        2 n.sub.D.sup.28 1.5474                         39    C.sub.2 H.sub.5                                                                   SC.sub.3 H.sub.7 (n)                                                                H      O 2-CH.sub.3,5-NO.sub.2                                                                  2 n.sub.D.sup.20 1.5566                         40    C.sub.2 H.sub.5                                                                   SC.sub.3 H.sub.7 (n)                                                                H      S 2-CH.sub.3,5-NO.sub.2                                                                  2 n.sub.D.sup.20 1.5822                         41    C.sub.2 H.sub.5                                                                   SC.sub.3 H.sub.7 (n)                                                                H      O                                                                                 ##STR16##                                                                             2 n.sub.D.sup.28 1.5481                         42    C.sub.2 H.sub.5                                                                   SC.sub.3 H.sub.7 (n)                                                                H      O 2,4,5-Cl.sub.3                                                                         3 n.sub.D.sup.28 1.5722                         43    C.sub.2 H.sub.5                                                                   SC.sub.3 H.sub.7 (n)                                                                H      S 2,4,5-Cl.sub.3                                                                         3 n.sub.D.sup.20 1.5994                         __________________________________________________________________________

EXAMPLE 6

    ______________________________________                                         Emulsifiable concentrate                                                       ______________________________________                                         Compound No. 16        20    weight %                                          Xylene                 75    weight %                                          Poloxyethylene glycol ether                                                                           5     weight %                                          (Nonipol 85 ®)                                                             ______________________________________                                    

An emulsifiable concentrate is produced by mixing the above ingredients.

EXAMPLE 7

    ______________________________________                                         Wettable powder                                                                ______________________________________                                         Compound No. 17        30    weight %                                          Sodium lignin sulfonate                                                                               5     weight %                                          Polyoxyethylene glycol ether                                                                          5     weight %                                          (Nonipol 85 ®)                                                             White carbon           30    weight %                                          Clay                   30    weight %                                          ______________________________________                                    

A wettable powder is produced by mixing the above ingredients.

EXAMPLE 8

    ______________________________________                                         Dust                                                                           ______________________________________                                         Compound No. 31      3     weight %                                            White carbon         3     weight %                                            Clay                 94    weight %                                            ______________________________________                                    

A dust is produced by mixing the above ingredients.

EXAMPLE 9

    ______________________________________                                         Granule                                                                        ______________________________________                                         Compound No. 9        10    weight %                                           Sodium lignin sulfonate                                                                              5     weight %                                           Clay                  85    weight %                                           ______________________________________                                          Granules are produced by mixing the above ingredients.

EXAMPLE 10

Testing Example 1: Effectiveness against Laodelphax striatellus

(a) A test compound was processed into an emulsifiable concentrate in accordance with the formulation of Example 6, followed by diluting with water to prepare a treating solution of a 40 ppm concentration. 2.5 ml of the treating solution was placed into a test tube (with 1.7 cm of diameter, 4 cm deep), in which three seedlings of a paddy-rice plant (on the 7th day after germination) were allowed to stand so their root portions were dipped into the solution for 2 hours. The seedlings were then transferred into a test tube having 1 ml water placed in the bottom, and ten third-instar larvae of Laodelphax striatellus were released. After allowing the test tube to stand in the room (28° C.) for 24 hours, the dead larvae were counted. The test is repeated twice, and the test results are tabulated, in terms of mortality, in Table 2 (I).

(b) A test compound was processed into a dust preparation in accordance with the formulation of Example 8, and 500 g of the preparation was dusted on the potted paddy-rice plant (1/5,000 a) by the Berger Duster method. After dusting, leaves (15 cm long) of the paddy rice were cut off and were placed in a test tube containing 1 ml of water in the bottom, and ten adults of Laodelphax striatellus were released therein. After allowing the test tube to stand in the room (28° C.) for 24 hours, the dead insects were counted. The test was repeated twice, and the test results, in terms of mortality, are tabulated in Table 2 (II).

                  TABLE 2                                                          ______________________________________                                                        Mortality, %                                                    Comp. No.        (I)     (II)                                                  ______________________________________                                          6               97      70                                                     9               100     75                                                    13               100     90                                                    16               97      75                                                    17               100     35                                                    18               100     100                                                   20               100     65                                                    22               85      63                                                    24               85      50                                                    29               95      30                                                    31               100     90                                                    33               100     65                                                    37               100     90                                                    42               100     40                                                    43               85      40                                                    Non-treated      0        0                                                    ______________________________________                                    

Testing Example 2: Effectiveness against Spodoptera litura

Twenty milliliters of a 500 ppm, water-diluted solution (with Dyne® Takeda Chem. Ind. Ltd., spreading agent, as diluted 3000-fold) of the test compound (the emulsifiable concentrate of Example 6) was sprayed on grown seedlings (10 days after germination) of soybean plant water-cultured in a polyethylene cup by the use of a spray gun (nozzle pressure of 1 kg/cm² gauge) in a spraying chamber. 2 hours after spraying, two main leaves of soybean plant were cut off and were placed into two cups (6 cm in diameter and 4 cm in depth), respectively, and ten second-instar larvae of Spodoptera litura were liberated. The cups were left in the room (28° C.) for 24 hours, and the dead larvae were counted. The test was repeated twice, and the test results in terms of mortality are tabulated in Table 3.

                  TABLE 3                                                          ______________________________________                                         Comp. No.                                                                               Mortality, %                                                                               Comp. No.   Mortality, %                                  ______________________________________                                         4        100         26          100                                           5        100         27          100                                           7        100         28          100                                           8        100         29          100                                           9        100         30          100                                           10       100         31          100                                           12       100         32          100                                           13       100         33          100                                           14       100         35          100                                           16       100         36          100                                           17       100         37          100                                           18       100         38          100                                           19       100         39          100                                           20       100         40          100                                           22       100         41          100                                           23       100         42          100                                           24       100         43          100                                           25       100         Non-treated  0                                            ______________________________________                                    

Testing Example 3: Effectiveness of Unaspis yanonensis

A test compound was processed into a wettable powder in accordance with the formulation of Example 7, and was diluted with water (with Dyne®, spreading agent, as diluted 3000-fold) to prepare a 500 ppm aqueous suspension. 20 ml of the aqueous suspension was sprayed on second-instar larvae (10 to 50 of the number parasitized) of Unaspis yanonensis on a seedling of Citrus trifoliate (2 months after germination) being planted in a pot (9 cm in diameter). After the sprayed pot was transferred to a greenhouse (25° to 30°C.), adult insects were counted on the 20th day after spraying. The test was repeated twice, and the test results in terms of mortality are tabulated in Table 4. Mortality (%) is calculated by the following equation: ##EQU1##

                  TABLE 4                                                          ______________________________________                                         Comp. No.                                                                               Mortality, %                                                                               Comp. No.   Mortality, %                                  ______________________________________                                         1        86          29          97                                            2        75          31          75                                            3        79          33          70                                            4        84          34          79                                            12       71          35          82                                            25       100         Non-treated  0                                            ______________________________________                                    

Testing Example 4: Effectiveness against Tetranychus urticae

A test compound was processed into an emulsifiable concentrate in accordance with the formulation of Example 6, and diluted with water (with Dyne®, spreading agent, as diluted 3000-fold) to prepare a 500 ppm aqueous solution. Ten female adults of Tetranychus urticae) were infected on the seedling of a kidney bean plant water-cultured in a polyethylene cup, and the cups were placed in a glass chamber (28° C.) for 24 hours, followed by spraying 20 ml of the aqueous solution on the kidney bean plant. After the sprayed cup was placed again in the glass chamber, the number of the adults and larvae living on the leaves was counted on the 2nd and 7th days after spraying. The test was repeated twice, and the test results are tabulated in Table 5 in terms of the efficacy grading as determined by calculating a decrease rate by the following equation:

Decrease rate (%)=[(number of mites tested-number of larvae living on the day of inspection)/(number of mites tested)]×100

    ______________________________________                                         Efficacy grading    Decrease rate, %                                           ______________________________________                                         0                   Not more than 20                                           1                   21 to 50                                                   2                   51 to 89                                                   3                   Not less than 90                                           ______________________________________                                    

                  TABLE 5                                                          ______________________________________                                         Efficacy grading            Efficacy grading                                   Comp. No.                                                                              2nd day  7th day Comp. No.                                                                               2nd day                                                                               7th day                               ______________________________________                                         1       3        3       21       3      0                                     3       3        0       22       3      3                                     4       3        3       23       3      3                                     5       3        3       24       3      3                                     7       3        3       25       3      3                                     8       3        0       29       3      3                                     9       3        3       30       3      3                                     10      3        3       31       3      3                                     11      3        0       32       3      3                                     12      3        3       33       3      3                                     13      3        3       35       3      3                                     14      3        0       36       3      3                                     15      3        0       37       3      3                                     16      3        3       38       3      3                                     17      3        3       41       3      3                                     18      3        3       42       3      3                                     19      3        3       43       3      3                                     20      3        3       Non-treated                                                                             0      0                                     ______________________________________                                    

REFERENCE EXAMPLE Toxicological Test

Below tabulated are the oral acute toxicity values obtained with five-week aged, ddY-SLC strained male mice:

    ______________________________________                                         Comp. No.                                                                               LD.sub.50, mg/kg                                                                           Comp. No.  LD.sub.50, mg/kg                               ______________________________________                                         1        >300        23         50 to 300                                      2        >300        24         >300                                           3        >300        25         >300                                           4        >300        26         >300                                           5        >300        27         50 to 300                                      6        >300        28         >300                                           7        >300        29         ca. 300                                        8        >300        30         >300                                           9        >300        31         >300                                           10       >300        32         >300                                           11       >300        33         >300                                           12       >300        34         >300                                           13       >300        35         ca. 300                                        14       >300        36         >300                                           15       >300        37         >300                                           16       >300        38         >300                                           17       >300        39         >300                                           18       >300        40         >300                                           19       >300        41         50 to 300                                      20       >300        42         >300                                           21       >300        43         >300                                           22       ca. 300                                                               ______________________________________                                     

What is claimed is:
 1. A compound represented by the formula: ##STR17## wherein R¹ is ethyl, R² is n-propylthio, X is an oxygen or sulfur atom, Y is alkyl of 1 to 4 carbon atoms, a halogen atom or trifluoromethyl, and n is an integer of 1, 2 or
 3. 2. A compound as claimed in claim 1, wherein X is oxygen.
 3. A compound as claimed in claim 1, wherein X is sulfur.
 4. A compound as claimed in claim 1, namely O-ethyl-O-[1-(4-bromophenyl)pyrazol-4-yl]-S-n-propyl phosphorothiolate.
 5. A compound as claimed in claim 1, namely O-ethyl-O-[1-(3-chlorophenyl)pyrazol-4-yl]-S-n-propyl phosphorothiolate
 6. A compound as claimed in claim 1, namely O-ethyl-O-[1-(4-chlorophenyl)pyrazol-4-yl]-S-n-propyl phosphorothiolate.
 7. A compound as claimed in claim 1, namely O-ethyl-O-[1-(4-chlorophenyl)pyrazol-4-yl]-S-n-propyl phosphorothiolothionate.
 8. A compound as claimed in claim 1, namely O-ethyl-O-[1-(4-fluorophenyl)pyrazol-4-yl]-S-n-propyl phosphorothiolate.
 9. A compound as claimed in claim 1, namely O-ethyl-O-[1-(3-trifluoromethylphenyl)pyrazol-4-yl]-S-n-propyl phosphorothiolate.
 10. An insecticidal-acaricidal composition which comprises as an active component an insecticidally or acaricidally effective amount of a compound represented by the formula: R1 ? ##STR18## wherein R¹ is ethyl, R² is n-propylthio, X is an oxygen or sulfur atom, Y is alkyl of 1 to 4 carbon atoms, a halogen atom or trifluoromethyl, and n is an integer of 1, 2 or 3, anda neutral carrier therefor. 